1. Field of the Invention
The field of art to which this invention pertains may be generally located in the class of devices relating to valves. Class 335, Electricity, Magnetically Operated Switches, United States Patent Office Classification, appears to be the applicable general area of art to which the subject matter similar to this invention has been classified in the past.
2. Description of the Prior Art
This invention relates to solenoids, and more particularly to solenoids adapted for use in operating miniature valves or like members. Heretofore, the prior art solenoids incorporated a round core iron construction comprising a cylindrical armature and a mating cylindrical pole piece. The disadvantage of such prior art solenoids is that the width of a solenoid with a round core iron construction is substantially increased to produce a solenoid with a given force at a given stroke. In miniature valve packages, the width of the valve and solenoid is of primary bottom flux plate which engages the lower end of the can. The upper end of the can is closed off with a flux carrying top plate, and the can is secured between the top and bottom flux plates by any suitable means, such as heat forming the flux plates to the bobbin flanges. An armature bushing is slidably mounted into the upper end of the bobbin, and it is rectangular in cross section, with rounded ends, so as to slidably fit within the similarly shaped cored hole in the bobbin. An elongated armature having a rectangular cross section, with rounded ends, is slidably mounted in the armature bushing. The inner end of the armature is engaged by a push pin which is slidably mounted through an axial bore formed through the pole piece. A top cover member is mounted on the top flux plate securing the aforementioned solenoid assembly to the valves or similar device.
The upper and lower ends of the armature are provided with a radially shaped end surface to insure the solenoid shifts fully even if the armature is cocked slightly when the solenoid is energized. The rectangular shape of the coil bobbin not only increases the ampere turns of the coil, but also increases the cross-sectional and surface areas of the armature and pole piece which turns the increased ampere turns into increases force.